Abstract
Purpose :
Bardet-Biedl Syndrome (BBS) is a syndromic disease characterized by obesity, hypogonadotropic hypogonadism, polydactyly, developmental delay, genitourinary abnormalities, renal disease, and retinal degeneration. Despite syndromic findings, patients often are misdiagnosed with nonsyndromic retinitis pigmentosa (RP). Fundus autofluorescence (FAF) imaging can be especially helpful in diagnosing inherited retinal degenerations (IRDs) by detecting outer retinal degeneration. Here we analyze wide-field FAF in adult patients with BBS to determine if unique patterns exist.
Methods :
Nine patients with genetically-confirmed BBS (6 females, 3 males; age range 18-65) were identified. Electronic medical records were reviewed for medical and ocular history, ocular clinical exam findings, and ocular imaging.
Results :
Past medical history revealed syndromic findings in all patients and suspicious family history elements in several patients. Prior to their BBS diagnosis, 4 of 9 patients had been diagnosed with nonsyndromic RP and one with Leber congenital amaurosis (LCA). Three patients had mutations in BBS1, one in BBS2, one in BBS4, one in MKKS, one in TTC8, and two in BBS10. Visual acuity varied from 20/50 to no light perception (NLP), but generally decreased with increasing age. Advanced cataracts prevented fundus visualization in one patient. Macular atrophy was present in 8 patients. Optical coherence tomography (OCT) showed macular loss of outer retinal structure in 8 patients. Seven patients displayed foveal hypoautofluorescence with concentric hyper- and hypoautofluorescence in a bullseye pattern. Six of 8 patients had few to no peripheral pigmentary changes/bone spicules on clinical exam, however wide-field FAF of these patients revealed extensive speckled or diffuse peripheral hypoautofluorescence.
Conclusions :
Despite other syndromic findings (which can be life-threatening), patients with BBS are often misdiagnosed with nonsyndromic RP. We conclude that, along with detailed medical and family history, specific imaging findings on wide-field FAF can aid in the diagnosis of BBS in adult patients with suspected IRDs by better delineating macular degeneration patterns and unearthing extensive peripheral hypoautofluorescence not always evident on clinical exam.
This is a 2021 ARVO Annual Meeting abstract.